1. Field of Invention
The present invention relates to the field of fiber-reactive dyes. It describes black mixtures of fiber-reactive dyestuffs and use thereof for dyeing hydroxy- and/or carboxamido-containing fiber material.
2. Description of the Prior Art
Various patent documents disclose dye mixtures of fiber reactive dyes and their use for dyeing hydroxy- and/or carboxamido-containing fiber material in black shades. Examples are U.S. Pat. No. 5,445,654 and U.S. Pat. No. 5,611,821, KR 94-2560 and Sho 58-160362. However the dyeing properties of these dye mixtures in view of special application methods, as well as their applicability to fiber material and the fastness properties of the dyed material, are in need of improvement in some instances. Additionally most known mixtures of reactive dyestuffs have to be dyed in the presence of 50 to 100 g/l of electrolyte salts. The patent documents WO 98/42784, WO 98/42785, WO 93/18224 and U.S. Pat. No. 5,330,539 describe dyes which can be dyed in the presence of low amounts of salt but in the absence of salt they give dyeings having only very poor color strengths.
As due to ecological and economic reasons the contamination of dye-house waste-water has to be reduced there is a demand for reactive dyestuffs, which are applicable in the presence of low amounts or even in the absence of electrolyte salts giving dyeings of a high color strength.